Prebreaker



C. A. RlETZ PREBREAKER Feb. 14, 1961 3 Sheets-Sheet 1 Filed Jan. 6, 1958N RN INVENTOR. CARL A. lP/ETZ C. A. RIETZ PREBREAKER Feb. 14, 1961 5Sheets-Sheet 2 Filed Jan. 6, 1958 M PN INVENTOR. CARL A. P/Erz BYATTORNEYS v Pw Rn wm Feb. 14, 1961 c. A. RIETZ PREBREAKER 3 Sheets-Sheet3 Filed Jan. 6, 195a INVENTOR.

CARL A. R/ETZ ATTORNEY5 United States Patent PREBREAKER Carl A. Rietz,San Francisco, Calif, assignor to Rietz Manufacturing (10., Santa Rosa,Califl, a corporation of California Filed Jan. 6, 1958, Ser. No. 707,402

Claims. (Cl. 146-482) This invention relates generally to machines forthe mechanical disintegration of various materials. More particularly itrelates to disintegrating apparatus of the rotary crusher mill type suchas is suitable for use in the food processing industry.

In industrial processes where it is desired to subject material tomechanical disintegration, it has been common to utilize mills of theaxial crusher type, which disintegrate by mechanical impact. One verysatisfactory mill of this type is disclosed in US. Patent 2,738,932, andmakes use of a horizontal rotor carrying a plurality of crusher orbreaker arms. Mills of this type are widely used in shredding andbreaking operations to produce a final product or in prebreakingoperations for the reduction in size of large blocks of material priorto subsequent fine disintegration or granulation.

There are many instances in which it is desirable to subject very hardfeed material to disintegration, for example, in the breaking up orchopping of large blocks of frozen meat, vegetables and similarmaterial, or the shredding and breaking up of bulky press cake.Materials in a hard or frozen block form are quite difiicult todisintegrate, particularly frozen foods which are generally shipped inlarge chunks ranging in size from 50 to 200 pounds. These blocks are notresponsive to normal distintegration in a crusher mill, since they tendto ride on the rotor with the arms working grooves in the blockmaterial. To facilitate thawing, however, it is necessary that theblocks be broken up in large quantities and relatively rapidly.Consequently the present practice is to slice off small layers orshavings of the frozen material with high speed rotating knifeassemblies or vertically operating power saws, prior to the breakingoperation. Use of such equipment is not only expensive but involves anadditional time-consuming operation.

It is an object of the present invention to provide a novel machinewhich is particularly applicable to the breaking and disintegration oflarge blocks of very hard or frozen material of the type described.

Another object of the invention is to provide a machine of the abovecharacter which is capable of exerting very high disintegrating forces,while maintaining a very fast through-rate of feed material to producethe disintegrated product.

Additional objects of the invention will appear from the followingdescription in which the preferred embodiment has been set forth indetail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure l is a plan view illustrating a machine incorporating the presentinvention.

Patented Feb. 14, 1961 ice Figure 2 is a front elevational viewillustrating the machine of Figure 1.

Figure 3 is a sectional view taken along the line 3-3 of Figure 1.

Figure 4 is a cross sectional view taken along the line 4-4 of Figure 1.

Figure 5 is a like view taken along the line 5-5 of Figure 1.

Figure 6 is a view looking toward the discharge end of the machine.

Figures 7, A, B, C, and D, illustrate the novel construction of thebreaker arms.

Figures 8, A and B, are details illustrating the construction of thedeflecting anvils.

Figure 9 is an enlarged detail view in section along the line 99 ofFigure 6, showing details of the discharge orifice plate.

The disintegrating machine illustrated in the drawings comprises anelongated horizontal rotor 10, one end of which is supported within theexternal bearing housing 12. The other end of the rotor is enclosedwithin the breaker housing 14. The breaker housing, which may befabricated in two parts, consists of a cylindrical breaker section 16and a hopper section 18.

The hopper section includes a lower cylindrical wall 20, a portion ofwhich is oifset, as at 22, so as to be spaced from a cylinder ofrevolution of the rotor 10. This construction is shown in Figure 4. Thewall 24 opposite the offset hopper portion is preferably provided withan upper outwardly flaring portion 24 to facilitate the feeding of largeblocks of material into the hopper. The upper wall portion 26 of thehopper is inclined from the receiving opening 28 forwardly to a line ofconnection 30 with the cylindrical section 16, as shown in Figure 3. Aswill be presently explained, this construction causes blocks of materialintroduced into the hopper to be urged forwardly into a corneredposition within the ofiset wall portion 22, and to be held there untilsufficiently disintegrated to pass into the cylindrical breaker section16.

The rotor 10 consists of a shaft 32 which is journalled at one end bythe exterior bearings 34 and 36. The overhanging end 38 of the shaftextends to a position adja cent but spaced from the discharge opening 40of the cylindrical breaker section. The spaced relationship of the shaftis maintained by the flange 42 on the forced thrust bearing 36, by thespacer sleeves 44 and 45, and by the locknut 46. The end of the shaftcarried by the bearings 34 and 36 can be provided with an extension 50for connection with suitable power driving means (not shown).

Mounted upon the shaft 32 within the breaker housing 14 are a pluralityof specially shaped vane-like breaker arms 52, such as illustrated indetail in Figures 7, A, B, C, and D. As illustrated each breaker arm hasa pointed, beak-like material engaging end or hook 56 which enables thearms to gouge and tear small chunks of material from even the hardestblocks of feed material. In addition, the cutting edge 60 trailing thepoint 56 fireferably curves radially outward, as illustrated in Figure7B, so as to insure the progressive shaving of additional material fromthe feed blocks. The breaker arms are also thickened at their baseportions 58 and inclined to the axis of the rotor shaft, for example asin Figure 7C, so as to urge the material being disintegrated toward thedischarge end 40 of the breaker housing.

placed by about 120,- and spaced axially along the shaft so as toprovide substantially equal zones of operation of adjacent arms.Desirably the breaker. structure nearest the discharge opening 40comprises a pair of breaker arms 53, displaced 180 from each other.

Figures 8A and 8B illustrate an improved construction of the stationarybreaker anvils 64. As illustrated the anvils are constructed to providea pointed protrusion 66 adapted to-hold the material being disintegratedin the path of the hooked breakertarms 52, and to assist in the initialtearing and shredding action. To facilitate a rapid through-rate ofdisintegrated material, which is a particular feature of the invention,the anvils are provided with a hardened impact face 67 inclined towardsthe discharge opening 40, preferably at an angle of about 20 to 30.relative to the axis of the rotor shaft. Preferably, the base portionsof the anvils are thickened, as at 68, with the sides tapering generallyinwardly as illustrated in Figure 8A to provide a sturdy taperedconfiguration. I have found that a desired breaking and disintegratingaction as well as a more positive conveying action can be achieved bypositioning the anvils 64 in a longitudinally spaced row in the bottomwall of the hopper section 18, as indicated in Figures 1 and 8, and inspaced relation about the breaker section 16, as shown in Figures 3 and5.

In the preferred embodiment illustrated the anvils are integrally castas part of the housing or housing sections forming the hopper andbreaker sections. This construction is preferred, particularly in foodhandling operation, because it facilitates cleaning and maintenance ofsanitary conditions within the housing. It will be understood that theoverhung shaft construction, permitting ready access to the housingthrough the discharge opening 40, also facilitates maintenance of properstandards of cleanliness and sanitation.

The discharge opening of the breaker housing can be provided with anorifice plate 70 of a construction adapted to cooperate with theterminal pair of breaker arms 53 to provide a final shearing of theproduct before discharge. Figures 6 and 9 illustrate anovel-construction of anorifice plate for this purpose. As shown theorifice plate is provided with a plurality of widely spaced, diagonallyradiating spokes 72 which permit a progressive cutting or shearing ofthe material between the spokes and the arms 53. Plates with radialspokes used heretofore have presented a problem in that a relativelylarge chunk of material would have to be cut in two almostinstantaneously, such cutting action frequently subjecting the orificeplate and rotating breaker arms to excessive pressures or torques. Withthe illustrated construction, it will be understood that a scissors-likeshearing action will occur radially inwardly or'outwardly, dependingupon whether the spokes 72 are canted in the direction of rotation or inthe direction opposed to the rotation as illustrated in Figure 6. Thisscissors actionpermits a rapid efficient cutting or shearing of theparticles being discharged, and at relatively low power input. p

The rate of discharge of the disintegrated material, as well as theeffectiveness of the above described shearing action, can be greatlyenhanced by the spacing and cross sectional shape of the spokes 72. Asillustrated in Figure 9, the leading edges 74 of thespok'es are bevelledto provide an inclined face' 75 terminating in a cutting edge 76,immediately adjacent the rotating breaker arms 53. This construction notonly provides an enhanced excess of 10 tons per hour. .of frozen meatare easily handled without bridging or cutting action but also permits amore rapid discharge of the disintegrated material in the generaldirection of rotation of the rotor shaft. The trailing edges of thespokes can also be bevelled, as illustrated at 78. It will be understoodthat the angular spacing of the spokes 72 serves to provide a measure ofcontrol over the size of the particles discharged through the orificeplate.

Operation of the machine as described above is as follows: the shaft 32is driven at a relatively low rate of speed, preferably at about 20 to30 r.p.m., thereby developing high breaking torques while keepingmaintenance and power requirements relatively low. The ma terialintroduced into the hopper adjacent the inclined wall 24 is immediatelygrabbed by the pointed ends of the breaker arms 52 and rotated into theoffset portion 22 of the hopper. Because of the hooked, outwardlytapering cutting edge of the breaker arms, the material being handled isquickly shredded and broken up and forced downwardly in the hopper intoshearing contact with the anvils 64. As the material is broken up it isforced by the breaker arms, and by the inclined faces of the anvils,toward the right as viewed in Figures 1 and 2, and into the cylindricalbreaker section16 of the housing. The initial action of the breaker armsis primarily a tearing and gouging action whereas, adjacent the anvilsthe action is a breaking, crushing and shearing action. It will beunderstood that the shearing action is due to the close proximity of therotating breaker arms to the anvils. Adjacent the discharge orificeplate 70, a progressive cutting or scissors-like shearing action isproduced due to the diagonally radiating cutting edges 76. Throughout adisintegrating operation, the overhung construction of the rotor shaft,in conjunction with the inclined faces of the arms 52 and anvils 64,insures a very fast throughrate .of disintegrated material.

By way of example, a relatively small machine having an overall lengthof about inches and developing 15 horsepower at 22 r.p.m. is able tocrush and chop frozen blocks of meat, ground bone, eggs, vegetables,fish, etc. on a very high capacity, continuous basis, at a rate in Onehundred-pound blocks choking at a rate of 3 or 4 per minute. A somewhatlarger machine using 30 horsepower or less is able to re duce such-pound blocks to an average 2-inch to 3- inch size at-a rate of up to 12tons per hour, accepting the blocks in any position without bridging orchoking.

I claim: 7

1. In a disintegrating machine: a housing including a hopper sectionhaving an opening for receiving feed material, and .a cylindricalbreaker section having an end opening for discharge of disintegratedmaterial; said hopper section having a lower cylindrical wall, a portionof which is offset so as to be spaced from a cylinder of revolutionpassing therethrough, and an upper wall portion inclined from saidreceiving opening forwardly to said cylindrical breaker section; a pairof spaced cylindrical bearings mounted externally of said hoppersection; a rotatable horizontal shaft journalled in said bearings so asto extend through the cylindrical portions of said hopper and breakersections, the extending end of said shaft being adjacent to but spacedfrom said discharge opening; a plurality of vane-like breaker armsangularly displaced Withrespect to each other and integral with saidshaft; each arm including a thickened web portion inclined with respectto the axis of the shaft so as to urge material being disintegratedtoward the discharge end of the housing, and a pointed, beak-likematerial engaging end; and spaced breaker anvils mounted on the housingand extending between paths of movement of said breaker arms, saidanvils being disposed to pass between adjacent breaker arms and spacedin relationship thereto so as to hold the material being disintegratedin the path of the pointed material engaging ends of said breaker arms.

2. A machine as in claim 1 in which said inclined and offset wallportions of the hopper section are slightly curved.

3. A machine as in claim 1 in which said breaker arms curve forwardly inthe direction of rotation of said shaft, and are provided with asharpened leading edge curving outwardly to a point.

4. A machine as in claim 1 wherein said cylindrical breaker section isprovided with a discharge orifice plate having spacing means adapted tolimit the size of disintegrated material being discharged.

5. A machine as in claim 1 wherein wall portions of the hopper sectionabove said offset portion are in a substantially vertical planeextending upwardly from said offset portion.

References Cited in the file of this patent UNITED STATES PATENTS230,708 Leopold Aug. 3, 1880 424,758 Brown Apr. 1, 1890 469,097 SeabergFeb. 16, 1892 1,170,963 Coolie Feb. 8, 1916 2,614,597 Magnus Oct. 21,1952 2,695,644 Talge et al. Nov. 30, 1954 2,738,932 Rietz Mar. 20, 19562,796,901 Autio June 25, 1957

